As both parties turn to the general election, and the potentially pivotal role of minority voters, battles over voter identification and other new state election laws are intensifying.

Voting rights groups, who say the new laws discriminate against minority voters, won a key victory Thursday with a federal judge's decision to strike down portions of a Florida law that tightened rules for third-party groups that register voters. In his opinion, U.S. District Court Judge Robert L. Hinkle said:

"Together speech and voting are constitutional rights of special significance; they are the rights most protective of all others, joined in this respect by the ability to vindicate one's rights in a federal court. ...[W]hen a plaintiff loses an opportunity to register a voter, the opportunity is gone forever ... And allowing responsible organizations to conduct voter-registration drives — thus making it easier for citizens to register and vote — promotes democracy."

The ruling comes as Florida faces similar challenges to its effort to purge its voter rolls of potential noncitizens. The Justice Department has filed suit to stop the practice, arguing that it violates the 1965 Voting Rights Act, which protects minorities, and the 1993 National Voter Registration Act, which governs voter purges.

The Tampa Bay Timesreported that Florida officials are considering fighting the lawsuit:

"We are firmly committed to doing the right thing and preventing ineligible voters from being able to cast a ballot," said Chris Cate, spokesman for Secretary of State Ken Detzner.

Florida also has been criticized for reversing rules that had made it easier for former felons to vote.

Since 2008, controversial changes to state election laws have spread across the nation to restrict voter registration drives, scale back early voting periods or stop people from registering to vote on Election Day. Before the changes, all three practices were credited with helping to increase the young and minority voter turnout in 2008 that elected President Obama.

Young and minority voters are expected to again be key in this year's election. That's why Obama's re-election campaign recently launched an effort to educate voters about the new requirements.

The campaign's new website, www.gottavote.org, helps voters register, lays out legal changes in all the states, and asks lawyers to volunteer their expertise in election law.

The effort is designed mainly to address the roughly 31 states that now have laws requiring voters to present identification at the polls. About 15 of the states have adopted the strictest rules, requiring people to show state-issued photo IDs.

The voter ID and other laws are the result of a push mostly by Republicans who say they want to prevent election fraud. Democrats and voting rights activists argue that they are unnecessary because voter fraud is rare — often citing the findings of a federal panel.

Opponents also say the laws are part of a Republican strategy to suppress turnout among eligible voters — particularly the young, the poor and African-Americans — who tend to favor Democratic candidates.

The Brennan Center for Justice at New York University, which opposes the laws, says as many as 5 million voters could be turned away at the polls. About 18 percent of seniors and 25 percent of African-Americans don't have state-issued photo identification, according to the center.

The Brennan Center, which represented plaintiffs in the Florida lawsuit, found the laws have passed primarily in presidential battleground states. The voter ID states hold 171 electoral votes, or 63 percent of the 270 votes needed to win the presidency.

Voter ID advocates cite numerous polls showing strong support among both Democrats and Republicans. A Rasmussen Reports survey in April found that 73 percent of respondents believe the ID requirement isn't discriminatory.

Supporters also say voter ID laws aren't intended to discourage voters, but to protect the authenticity of their ballots. In Virginia, after Gov. Bob McDonnell signed a new voter ID bill recently, he issued an executive order directing the state to send new registration cards to every active voter.

The move by McDonnell, a Republican, is unusual among voter ID states and is widely seen as an effort to blunt accusations that the state is trying to suppress voter turnout. McDonnell wrote in his executive order:

"All eligible voters regardless of income, race, age, and other factors should be able to have equal access to the electoral process and should be made aware of any changes that may impact their ability to vote."

At the center of many of these legal challenges is Attorney General Eric Holder. His Justice Department has gone to court to overturn numerous state laws and blocked implementation of voter ID laws in states such as South Carolina. In each case, the Justice Department has argued that the laws would disenfranchise minority voters.

On Wednesday, Holder told a gathering of the Congressional Black Caucus that "both overt and subtle forms of discrimination remain all too common and have not yet been relegated to the pages of history."

Holder continued:

"If a state passes a new voting law and meets its burden of showing that the law is not discriminatory, we will follow the law and will approve that change. ... When a jurisdiction fails to meet its burden in proving that a voting change will not have a racially discriminatory effect, we will object, as we have in 15 different cases."

Critics complain that Holder is taking an unabashedly, and unethically, political stance against voter ID laws. They say that, as the nation's top law enforcement officer, Holder instead should be enforcing these laws, particularly since the Supreme Court upheld Indiana's voter ID measure in 2008.

That ruling found that requiring voters to produce identification is not unconstitutional, and that states have a "valid interest" in improving election procedures and deterring fraud. Supporters believe the decision should have settled the controversy.

On Friday, The Wall Street Journal's conservative editorial board accused Holder, who is African-American, of trying to "inflame racial antagonism":

"The United States of America has a black President whose chief law enforcement officer, Attorney General Eric Holder, is also black. They have a lot of political power. So how are they using it? Well, one way is to assert to black audiences that voter ID laws are really attempts to disenfranchise black Americans. And liberals think Donald Trump's birther fantasies are offensive?"

"... The two most powerful men in America are black, two of the last three Secretaries of State were black, numerous corporate CEOs and other executives are black, and minorities of many races now win statewide elections in states that belonged to the Confederacy, but the AG implies that Jim Crow is on the cusp of a comeback."

The editorial says Holder's strategy is to scare minorities into seeing voter ID laws as a threat, hopefully energizing them to turn out for Obama in large numbers in November.